Psst—wanna know a secret? Doors Open is spilling plenty of them for its 15th edition.

Built around the theme of “Secrets and Spirits,” this year’s Doors Open focuses on hidden places, and encounters with the otherworldly. Secret passages, ghosts, and unsolved mysteries will fill the stories heard by participants at more than half of the 155 locations participating this Saturday, May 24, and Sunday, May 25, as well as a slate of tie-in walking tours.

This year’s new participants offer much of interest to those intrigued by this year’s theme and to those who believe spirits are bunk (and to those anxious to get a closer look at the TTC’s new streetcars). Here are some of the debuting sites—ranging in age from over 200 years to less than one year old—that caught our attention.

An eclectic slate of activities is promised by the current tenants of a former toy factory built in 1907. Besides four daily tours, visitors can enjoy a tarot reading, check out costumes and props, watch special effects makeup demos, sample food, and enjoy a “KISS smoking guitar demo.” Fire breathing may or may not be encouraged.

Built in 1836, this farmhouse was long occupied by the descendants of William Cornell, a Scarborough pioneer who owned the township’s first orchard and sawmill and helped carve Kingston Road out of the wilderness. Its residents established a long record of public service, which extended through to the 1970s via Metro Toronto chairman Albert M. Campbell. Visitors can tour the home and the gardens on the grounds.

One of the few surviving structures from the Town of York era, this landmark has watched over our waters since 1808—and certainly fits in nicely with this year’s ghostly theme. Legends surround original lighthouse keeper John Paul Rademuller, who mysteriously disappeared in 1815. In some versions of the tale, Rademuller learned the hard way not to deprive soldiers of illicit booze. Whatever his fate was, his ghost is reputed to haunt the tower. While visitors might not encounter Rademuller’s spectre, they can walk up to the top for a view of the Toronto Islands. The official site warns the climb is not for the claustrophobic.

When it comes to historic Toronto waterworks, most people think of the R.C. Harris Water Treatment Plant (which is participating in Doors Open this year). Closer to downtown, though, is this century-old gem, the city’s oldest operating pumping station. It’s one of a series of facilities that transport water from the lake to higher elevations. Thanks to the additions made to it over the years, the building can inspire a solid game of “guess the architectural style.”

School’s in at Parkdale Collegiate, which celebrates its 125th anniversary this month (though the current building dates from 1929). Wander the halls, and check out its auditorium and war memorials. Detention slips will not be handed out.

If you haven’t inspected the TTC’s new streetcars, here’s a chance to do just that before they enter service this August. Besides the shiny new model, visitors can check out classic Peter Witt and PCC streetcars in a yard that has serviced transit vehicles since it opened as a paint shop for the Toronto Railway Company in 1913.

Once upon a time, there was a comic book called House of Secrets. St. John’s itself could be given that title—it’s a circa-1908 church containing secret passages, an attic filled with abandoned projects, and an unexcavated basement. Not-so-hidden attractions include the original pipe organ and the National Presbyterian Museum.

The former residence of Senator Frank O’Connor (founder of the Laura Secord candy chain, political bigwig, and namesake of O’Connor Drive), O’Connor House has undergone a multimillion-dollar restoration. Both the home and the neighbouring high school will be open for touring.

Opened in March, the Theatre Centre shows off its new home in the century-old Carnegie Library. Besides touring the facilities, visitors will view preparations for Mammalian Diving Reflex’s upcoming presentation, Promises to a Divided City.

UPDATE: May 21, 2014, 3:10 PM An earlier version of this post indicated that the Fort York Library would be participating in Doors Open Toronto this year; that no longer appears to be the case.